Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q21/00—Antenna arrays or systems
  • H01Q21/0006—Particular feeding systems
  • H01Q21/0037—Particular feeding systems linear waveguide fed arrays
  • H01Q21/0043—Slotted waveguides
  • H01Q21/005—Slotted waveguides arrays
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
  • H01P5/00—Coupling devices of the waveguide type
  • H01P5/04—Coupling devices of the waveguide type with variable factor of coupling
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
  • H01P5/00—Coupling devices of the waveguide type
  • H01P5/08—Coupling devices of the waveguide type for linking dissimilar lines or devices
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01P—WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE
  • H01P5/00—Coupling devices of the waveguide type
  • H01P5/12—Coupling devices having more than two ports
  • H01P5/16—Conjugate devices, i.e. devices having at least one port decoupled from one other port
  • H01P5/19—Conjugate devices, i.e. devices having at least one port decoupled from one other port of the junction type
  • H01P5/20—Magic-T junctions
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01Q—ANTENNAS, i.e. RADIO AERIALS
  • H01Q21/00—Antenna arrays or systems
  • H01Q21/06—Arrays of individually energised antenna units similarly polarised and spaced apart
  • H01Q21/061—Two dimensional planar arrays
  • H01Q21/064—Two dimensional planar arrays using horn or slot aerials

Definitions

• the present invention relates to a feeding network structure for a flat type antenna, and more particularly, to a feeding network structure for a flat type antenna, which reduces sidelobes by controlling radio wave transmission and reception intensities so that a center of an antenna has radio wave transmission and reception intensities higher than a peripheral portion by configuring a "T" type distributor of a feeding network in an asymmetrical structure having different widths.
• the microwave represents an electromagnetic wave having a wavelength of 1 mm (300 Hz) to 1 m (30 GHz). Since the microwave has a frequency higher than a very high frequency, the microwave is called an ultra high frequency.
• the microwave is divided into an EHF (Extremely High Frequency) having a wavelength of several millimeters, an SHF (Super High Frequency) having a wavelength of 1 to 10 cm, and a UHF (Ultra High Frequency) having a wavelength of 0.1 to 1 m for each wavelength area.
• EHF Extremely High Frequency
• SHF Super High Frequency
• UHF Ultra High Frequency
• a waveguide is used as a transmission passage of such microwave.
• the waveguide is a metallic pipe used in transmission of the microwave. Since a radio wave may be diverged from a surface of a metallic conductor to the air at the time of using the metallic conductor to guide the radio wave transmitted from a radio transmitter to an antenna, a method of guiding the radio wave into the metallic pipe is used.
• the waveguide has low resistance loss and low dielectric loss, no radiation material, functions as a high-pass filter and large power, has large available power, and can be isolated from an external electromagnetic field.
• a type of the waveguide includes a rectangular shape, a round shape, an oval shape, and the like.
• a sectional dimension is determined by the lowest transmittable frequency (cut-off frequency).
• a flat-type antenna using the waveguide includes a waveguide antenna.
• the waveguide antenna includes an upper panel and a lower panel each having waveguides corresponding to each other on a top surface and a bottom surface of each of the upper panel and the lower panel. Cells of the upper panel are opened through the top surface of the upper panel. The upper panel and the lower panel have conductivity.
• a feeding network structure of the existing waveguide antenna has been designed to obtain the maximum antenna gain by supplying the maximum power to the cell at equivalent intensity.
• An asymmetrical waveguide T type distributor structure has also been used as the feeding network structure of the waveguide antenna due to a size of the antenna.
• an arrangement structure of the asymmetrical waveguide distributor used herein was just a pipeline for supplying a radio wave of equivalent intensity to all the cells.
• An array antenna in which the radio wave is supplied to each cell with the equivalent intensity has a demerit in that the sidelobes are very high.
• the antenna having the high sidelobes may be weak to tapping of transmission and reception signals by a third party and radio wave interference in communication between base stations. Particularly, a reception error caused by the sidelobes often occurs in a region where satellites are densely arranged, such as Europe.
• a method for enhancing a sidelobe characteristic of the waveguide antenna includes a first method of avoiding a sidelobe beam direction of the waveguide antenna and a second method of controlling output intensities of stacked cells of the waveguide antenna.
• the sidelobe itself is not reduced, but it is just avoided as well as it is difficult to design the waveguide antenna compactly in a rectangular shape.
• the second method most of the waveguide antennas have a structure for maximizing the antenna gain rather than the sidelobe.
• the existing waveguide antenna was not an antenna having low sidelobes except the method of avoiding the sidelobe beam direction to another direction.
• An object of the present invention is to provide a feeding network structure of a flat type antenna capable of reducing sidelobes without changing a structure in order to reduce the sidelobes in a configuration similar to an existing waveguide antenna.
• Another object of the present invention is to provide a feeding network structure of a flat type antenna capable of reducing the side lobes by asymmetrical outputs of stacked cells of the waveguide antenna.
• Technical Solution [14] In order to achieve the above-described object, according to the present invention, there is provided a feeding network structure of a flat type antenna formed on at least one surface of the flat type antenna.
• two branch lines of a "T" type distributor branched in the same direction as a direction to reduce sidelobes in a feeding network are formed in an asymmetrical structure in which a branch line comparatively closer to a center of the flat type antenna has a width larger than the other branch line so that power distribution of a radio wave becomes larger toward the center of the flat type antenna from both ends of the flat type antenna on the basis of the direction to reduce the sidelobes.
• the flat type antenna may be a waveguide antenna with a waveguide, which serves as the feeding network, formed on a conductive panel, and two branch lines of the "T" type distributor branched in the same direction as a direction to reduce the sidelobes in a waveguide may be formed in an asymmetrical structure in which a branch line comparatively closer to a center of the conductive panel has a width larger than the other branch line so that the power distribution of the radio wave becomes larger toward the center from both ends of the conductive panel on the basis of the direction to reduce the sidelobes.
• the waveguide antenna may include a lower panel with a lower waveguide formed on a top surface thereof and an upper panel with an upper waveguide, which corresponds to the lower waveguide, formed on a bottom surface thereof, and a cell of the upper waveguide may be opened through the top surface of the upper panel.
• the feeding network structure may further include a horn antenna formed by installing a horn being in communication with the opened cell of the upper panel on a conductive panel and coupled to the top surface of the upper panel.
• the feeding network structure may further include a slot antenna formed by installing slots on a conductive panel and coupled to the top surface of the upper panel.
• Some of the "T" type distributors of the feeding network may be formed in the asymmetrical structure in which the two branch lines have the widths different from each other.
• All "T" type distributors of the feeding network may be formed in the asymmetrical structure in which the two branch lines have the widths different from each other.
• the "T" type distributor of the feeding network may be formed in the asymmetrical structure in which the two branch lines have the widths different from each other.
• the "T" type distributor of the feeding network may be formed in a symmetrical structure in which the two branch lines have the same width, and an additional conductor for reducing the width may be disposed on a branch line comparatively distant from the center of the flat type antenna.
• the two branch lines of the "T" type distributor of the feeding network may be formed in the symmetrical structure in which the two branch lines have the same width, and a protrusion portion for reducing the width may be formed on an inner surface of a branch line comparatively distant from the center of the flat type antenna.
• the flat type antenna may be a microstrip antenna with a microstrip line, which serves as the feeding network, formed on a substrate, and two branch lines of a "T" type distributor branched in the same direction as the direction to reduce the sidelobes in the microstrip line may be formed in the asymmetrical structure in which a branch line comparatively closer to a center of the substrate has a width larger than the other branch line so that the power distribution of the radio wave becomes larger toward the center of the substrate from both ends of the substrate on the basis of the direction to reduce the sidelobes.
• FIG. 1 is a perspective view illustrating a whole configuration of a waveguide antenna according to a first embodiment of the present invention.
• FIG. 2 is a perspective view of the lower panel of the waveguide antenna according to the first embodiment of the present invention.
• FIG. 3 is a plan view of the lower panel of the waveguide antenna according to the first embodiment of the present invention.
• FIG. 4 is a plan view of a waveguide antenna according to a second embodiment of the present invention.
• FIG. 5 is a plan view of a waveguide antenna according to a third embodiment of the present invention.
• FIG. 6 is a plan view of a waveguide antenna according to a fourth embodiment of the present invention.
• FIG. 7 is a perspective view of a whole configuration of a waveguide antenna according to a fifth embodiment of the present invention.
• FIG. 8 is a plan view of a lower panel of the waveguide antenna according to the fifth embodiment of FIG. 7.
• WAVEGUIDE 112: "T” TYPE DISTRIBUTOR, 112a,112b: BRANCH LINE, 113: LOWER CELL, 120: UPPER PANEL, 121: UPPER CELL, 130: HORN ANTENNA, 131: HORN Best Mode for Carrying Out the Invention
• FIG. 1 is a perspective view illustrating a whole configuration of a waveguide antenna according to a first embodiment of the present invention.
• FIG. 2 is a perspective view of a lower panel of the waveguide antenna according to the first embodiment of the present invention.
• FIG. 3 is a plan view of the lower panel of the waveguide antenna according to the first embodiment of the present invention.
• a waveguide antenna 100 according to the first embodiment of the present invention includes a lower panel 110 and an upper panel 120.
• the waveguide antenna 100 may further include a horn antenna 130.
• the waveguide antenna 100 includes the lower panel 110 having a lower waveguide 111 serving as a feeding network formed on a top surface thereof and the upper panel 120 having an upper waveguide corresponding to the lower waveguide 111 of the lower panel 110 formed on a bottom surface thereof.
• the upper panel 120 and the lower panel 110 each have conductivity.
• the upper panel 120 and the lower panel 110 according to this embodiment have a rectangular, but the present invention is not limited to it, and the upper panel 120 and the lower panel 110 may have various shapes including a square shape, and the like.
• the waveguide antenna 100 is formed by coupling one upper panel 120 and one lower panel 110, but the present invention is not limited to it, and the waveguide antenna 100 may be formed by coupling two or more upper panels and two or more lower panels or by forming a waveguide in an inside of a single panel.
• two branch lines 112a and 112b of a "T" type distributor 112 branched in a direction to reduce sidelobes are asymmetrical to each other in different widths. That is, among the two branch lines 112a and 112b of the "T" type distributor 112, the branch line 112a positioned comparatively closer to a center on the basis of both ends in the direction to reduce the sidelobes has a width larger than the other branch line 112b.
• a front end of the lower waveguide 111 forms a lower cell 113.
• the upper panel 120 has the upper waveguide corresponding to the lower waveguide 111 of the lower panel 110 formed on the bottom surface thereof.
• An upper cell 121 of the upper waveguide is opened through a top surface of the upper panel 120.
• the waveguide antenna 100 may be formed by coupling the horn antenna 130 onto the top surface of the upper panel 120.
• the horn antenna 130 is formed by installing a horn 131 being in communication with the upper cell 121 of the upper panel 120 on a conductive panel.
• Graphs 1 to 3 show the radiation characteristic of a general waveguide antenna having a structure in which power of the radio wave is equivalently distributed to cells of the waveguide.
• Graphs 4 to 6 show the radiation characteristic of the waveguide antenna having a structure in which the power distribution of the radio wave in the direction of the center portion of the waveguide is gradually increased according to the first embodiment of the present invention.
• the radiation characteristic of the waveguide antenna according to the first embodiment of the present invention reduces the sidelobes in comparison with the radiation characteristic of the existing waveguide antenna. Therefore, in the waveguide antenna 100 according to this embodiment, a phenomenon that a radio wave generated in a direction except a direction of a is received by is remarkably reduced and thus interference caused by adjacent satellites or other noise is remarkably reduced, resulting in improving a radio wave reception characteristic of the waveguide antenna 100.
• the waveguide antenna 100 according to the first embodiment of the present invention is used in a region where satellites are densely arranged, such as Europe, it is possible to acquire a larger effect.
• An asymmetrical structure may be applied to all "T” type distributors formed in the waveguide of the waveguide antenna and the asymmetrical structure may be applied to only some "T” type distributors in the same manner as in this embodiment.
• FIG. 4 is a plan view of the waveguide antenna according to the second embodiment of the present invention.
• the asymmetrical structure is also applied to two branch lines 202a and 202b of a "T" type distributor 202 directly connected to a cell 203, which are opposite to each other. That is, even in the "T" type distributor 202 connected to the cell 203 of the waveguide antenna 200, the branch line 202a comparatively closer to a center of the waveguide antenna 200 among the branch lines 202a and 202b in two opposite directions has a width larger than the opposite branch line 202b.
• the power distribution of the radio wave becomes larger toward the center of the waveguide antenna 200 in comparison with the waveguide antenna 100 according to the first embodiment of FIGS. 1 and 2. That is, in the waveguide antenna 200 according to this embodiment, the sidelobes are further reduced in comparison with the waveguide antenna 100 according to the first embodiment of FIGS. 1 and 2.
• the waveguide antenna does not always have an excellent transmission and reception characteristic. Therefore, it is possible to control the sidelobes by properly adjusting an application position of the asymmetrical structure to the "T" type distributor of the waveguide antenna in consideration of a position of a peripheral radio wave generation source and a relationship with the peripheral radio wave generation source for receiving the radio wave.
• FIG. 5 is a plan view illustrating the structure of the "T" type distributor of the waveguide antenna according to the third embodiment of the present invention.
• widths of two branch lines 302a and 302b of the "T" type distributor 302 opposite to each other are asymmetrical to each other by a conductor 303 through coupling a conductor 303 to the branch line 302a comparatively closer to a center of the waveguide antenna 300 among the two branch lines 302a and 302b opposite to each other. That is, the branch lines 112a and 112b themselves of the "T" type distributor 112 are asymmetrical to each other in the waveguide antenna 100 according to the first embodiment of FIGS.
• the waveguide antenna 300 employing the "T" type distributor 302 having the above-described configuration may also reduce the sidelobes in the same principle as the waveguide antenna 100 according to the first embodiment of FIGS. 1 to 3.
• FIG. 6 is a plan view illustrating the structure of the "T" type distributor of the waveguide antenna according to the fourth embodiment of the present invention.
• a protrusion portion 403 for reducing a width of a branch line 402a comparatively closer to a center of the waveguide antenna 400 among two branch lines 402a and 402b opposite to each other is formed on an inner surface of the branch line 402a.
• Reference numeral 404 that is not described represents a cell of the waveguide antenna 400.
• the waveguide antenna 400 employing the "T" type distributor 402 having the above-described configuration also may reduce the sidelobes in the same principle as the waveguide antenna 100 according to the first embodiment of FIGS. 1 to 3.
• FIG. 7 is a perspective view illustrating a whole configuration of the waveguide antenna according to the fifth embodiment of the present invention.
• FIG. 8 is a plan view of a lower panel of the waveguide antenna according to the fifth embodiment of FIG. 7.
• a waveguide antenna 500 according to the fifth embodiment of the present invention includes a conductive lower panel 510, a conductive upper panel 520, and a slot antenna 530.
• the lower panel 510 has a lower waveguide 511 formed on a top surface thereof and the upper panel 520 has an upper waveguide (not shown), which corresponds to the lower waveguide 511 of the lower panel 510, formed a bottom surface thereof.
• the upper panel 510 and the lower panel 520 according to this embodiment have the square shape.
• two branch lines 512a and 512b of the "T" type distributor 512 branched in the direction to reduce the sidelobes have different widths and are asymmetrical to each other. That is, among the two branch lines 512a and 512b of the "T" type distributor 512, the branch line 512a positioned comparatively closer to a center on the basis of both ends in the direction to reduce the sidelobes has a width larger than the other branch line 512b.
• a front end of the lower waveguide 511 forms a lower cell 513.
• the upper panel 520 has the upper waveguide corresponding to the lower waveguide 511 of the lower panel 510 formed on the bottom surface thereof.
• An upper cell 521 of the upper waveguide is opened through a top surface of the upper panel 520.
• the waveguide antenna 500 may be formed by coupling the slot antenna 530 onto the top surface of the upper panel 520.
• the slot antenna 530 is formed by installing a plurality of slots 531 on a conductive panel.
• the feeding network of the flat type antenna has been described by using the waveguide antenna serving as the flat type antenna, the present invention is not limited to it and the feeding network structure may be applied to all flat type antennas with a feeding network formed on at least one surface thereof.
• the feeding network structure may be applied to a microstrip antenna with a microstrip line, which serves as the feeding network, formed on a substrate. That is, among two branch lines of a "T" type distributor branched in the direction to reduce the sidelobes in the microstrip line, a branch line comparatively closer to a center of the substrate may have a width larger than the other branch line in the asymmetrical structure so that power distribution of the radio wave becomes larger toward the center of the substrate from both ends of the substrate on the basis of the direction to reduce the sidelobes.

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• Variable-Direction Aerials And Aerial Arrays (AREA)
• Waveguide Aerials (AREA)
• Aerials With Secondary Devices (AREA)

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ID=40901267

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Family Applications After (1)

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Cited By (4)

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Citations (5)

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• 2008
  • 2008-05-22 WO PCT/KR2008/002842 patent/WO2009093779A1/en active Application Filing
• 2009
  • 2009-01-23 WO PCT/KR2009/000385 patent/WO2009093875A2/ko active Application Filing
  • 2009-01-23 KR KR1020090005946A patent/KR101035093B1/ko not_active IP Right Cessation
  • 2009-01-23 EP EP09704021.6A patent/EP2237371A4/en not_active Withdrawn

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